1. Field of the Invention
The present invention relates to attaching an airbag to the interior of a vehicle. More specifically, the present invention relates to novel methods and apparatus for attaching an inflatable cushion airbag to an interior surface of a vehicle.
2. Description of Related Art
Inflatable airbags are well accepted for use in motor vehicles and have been credited with preventing numerous deaths and injuries. In fact, the inclusion of inflatable safety restraint devices, or airbags, is now a legal requirement for many new vehicles. Airbags are typically installed in the steering wheel and in the dashboard on the passenger side of a car. In the event of an accident, an accelerometer within the vehicle measures the abnormal deceleration and triggers the ignition of a pyrotechnic charge. Expanding gases from the charge fill the airbags, which immediately inflate in front of the driver and passenger to protect them from impact against the windshield. Side impact airbags have also been developed in response to the need for similar protection from impacts in a lateral direction, or against the side of the vehicle.
Recently, airbag technology has continued to advance such that curtain airbags are now enlisted to provide roll-over protection as well as side impact protection. During a roll-over accident, the vehicle occupants can be jostled considerably, thereby causing the occupant to impact various parts of the vehicle interior. Even worse, the occupant may be ejected from the vehicle. Alternatively, a head or limb of an occupant may extend outside the vehicle during the roll-over. Such “occupant excursion” during roll-over accidents is a common cause of automotive fatality, particularly in the case of vehicle occupants that are not wearing a seat belt during the roll-over.
Conventional curtain airbags attempt to combat the dangers of side impact or roll-over accidents by having a curtain airbag unroll or unfold downward from the roof of the vehicle and then inflate beside the person as a means of preventing the person from hitting the door or window. Since a vehicle occupant may be leaning forward, reclined in the seat, or at any position in between, such curtain airbags are usually designed to be long enough to cover the whole interior side of the vehicle, protecting occupants in both front and rear passenger compartments.
To provide side impact and roll-over protection, curtain airbags are sized to hold large volumes of inflation gas and descend below the window sill. Consequently, when not inflated, the curtain airbag includes a significant amount of airbag material. Generally, the material is rolled or folded tightly into a long tubular bundle. During the inflation process, the curtain unrolls or unfolds along a side of the vehicle. The curtain may be kept rolled or folded by a sock that fits around the curtain.
To function properly, the curtain is stored and mounted either on or proximate a roof rail of the vehicle. When the curtain is inflated, the curtain breaks through the sock and descends. Inflation gas fills the curtain from the top of the vehicle toward the bottom. Typically, the curtain airbag is mounted to the roof rail or other parts of the vehicle by a plurality of connectors attached to cushion mount points. These connectors can take a variety of forms including fasteners, bolts, screws, rivets, hooks, rods, cables, brackets, push in clips, nails, cables, jigs, or the like. These fasteners secure the curtain to the vehicle during deployment. For example, in some curtains, an anchor mount point may be located at each end, and intermediate mount points may be dispersed at points in between. Generally, the mount points are portions of the curtain airbag which extend through the sock.
Generally, the roof rail is small and narrow. The area inboard of the roof rail is also small and narrow to provide an appealing and spacious vehicle interior for occupants. Thus, area where an inflatable curtain is installed is usually very narrow. Interior trim panels and/or a headliner typically conceal the inflatable curtain. The headliner is the material covering the interior roof, thereby making the roof of the vehicle more attractive to occupants. Typically, the headliner curves down along the sides of the roof and covers the roof rail. The edges of the headliner may be secured by door molding, trim, or the like.
The mount points are used to secure the curtain onto or proximate the roof rail of the vehicle. However, because of the size of the inflatable curtain and the small and narrow area around the roof rail and headliner, the installation of the airbag can be very difficult and cumbersome. For example, the contour and shape of the roof rail to which the curtain is mounted may cause the curtain to hang out away from the roof rail. Furthermore, the curtain may become pinched or bunched up by the headliner or trim causing an unsightly bulge or lump in the headliner. Alternatively, besides the inflatable curtain, various other components of the vehicle may also need to be installed in this space including assist grip handle brackets, hand grips, lighting fixtures, sun or moon roof brackets, hanger hook brackets, wiring, drain hoses, heating and ventilation (HVAC) controls, ducts and other parts. As such, even slight variations in the curtain's position may interfere with the installation of these components as well as the trim panels and headliner.
To address these issues, many airbag manufacturers presently employ a two step process for installing inflatable curtain airbags. First, the curtain must be held in place during the installation process. This can be done by either having multiple workers hold the airbag or by attaching the airbag to sophisticated jigs, hooks, or mounting brackets that have been placed into slots in the body of the vehicle. Once the airbag has been secured in the proper position, the workers are free to bolt the curtain airbag assembly to the vehicle using a connectors such as fasteners, bolts, screws, rivets, hooks, rods, cables, brackets, push in clips, nails, cables, jigs, or the like. Usually these connectors are threaded into holes, slits, or apertures that have been put into the top of the curtain airbag to facilitate the assembly process.
Unfortunately, this two step installation process poses serious cost and time constraints on airbag and vehicle manufacturers. Even if they work together, it will likely take multiple employees several minutes to install each unit using this method as they will have to position the airbag, thread each connector into the appropriate hole, and then tighten each connector to the appropriate load. As the manufacturer incurs costs for every moment that passes during the manufacturing process, these several minutes significantly affect the total production costs and the manufacturer's overall profit margin.
Moreover, the use of connectors to attach the curtain airbag to the vehicle creates additional problems for airbag and vehicle manufacturers. For example, such connectors increase the total number of parts required to produce the vehicle and each additional part has associated manufacturing, tooling, and design costs. Other connectors add bulk to the airbag such that the manufacturers cannot easily fold or position the airbag within the vehicle. Still other connectors have a tendency to damage the airbag, thereby requiring manufacturers to employ valuable resources in repairing and replacing damaged airbags.
Yet further, some connectors have been found to be difficult to use or install on the vehicles. Specifically, bolt/nut combinations require access to a rear portion of a vehicle surface in order to effect attachment, thereby requiring the manufacturer to delay assembly of other parts of the vehicle to accommodate installation of the cushion member. Other connectors such as screws or bolts may need to be threaded through the proper holes and tightened. The tightening process may require that an operator use considerable care to tighten each connector to the appropriate load. Even when non-threaded connectors are used, many known devices must be oriented with some care before they can provide effective fastening. As a result, installation personnel must not only keep the cushion member properly aligned with the vehicle surface, but must simultaneously rotationally align the connector with its mating portion of the vehicle surface.
Lastly, the use of many known connectors may negatively impact the customer's opinion of the both the airbag system and the vehicle in general. For example, some known connectors add to the weight of the vehicle, thereby reducing the overall handling, acceleration, and fuel economy of the vehicle. Still other known connectors often contain surfaces that rub undesirably against each other, thereby producing squeaks, rattling, or other disconcerting sounds. Such sounds may, for a common consumer, be interpreted as indicia of poor quality, even though the airbag cushion has been properly installed.
Accordingly, it would be an advancement in the art to create a novel apparatus and method for mounting a curtain airbag without the use of connectors such as fasteners, bolts, screws, rivets, hooks, rods, cables, brackets, push in clips, nails, cables, jigs, or the like. It would be a further advancement to provide an airbag attachment system that could mount the airbag to the vehicle in one single step. It would be another advancement to provide an airbag mounting system that holds the airbag tightly against the roof rail higher up against the roof rail such that the attached airbag does not occupy or interfere with the space needed to properly assemble the headliner. Additionally, it would be an advancement to provide an airbag mounting system that attaches the airbag to the vehicle quickly, easily, and inexpensively, thereby reducing the production costs, installation time, and the possibility of installation error.